Communication devices capable of wireless interfacing and methods for associating said devices

ABSTRACT

The invention concerns a method for associating communication devices capable of wireless interfacing. It consists in producing a relationship between communication devices capable of wireless interfacing enabling dialogue among them exclusively. The devices comprise a single and permanent identifier, can be connected to a cable network and exchange data through the latter. The association is characterized in that it can be modified by connecting the devices to be associated to a single cable network. The invention also concerns the device for implementing said method.

[0001] The present invention concerns communication networks, moreparticularly devices capable of wireless dialog connected to thesenetworks and methods of associating said devices.

[0002] There is currently an effort to define standards for linkingcommunication buses by using a wireless communication technology.Parallel efforts have been made under the patronage on the one hand ofthe IEEE (IEEE P1394.1 “Draft Standard for High performance Serial BusBridges”) and, on the other hand, by the ETSI (“Broadband Radio AccessNetwork (BRAN); HIPERLAN Type 2 Technical Specification; Packet basedconvergence layer”).

[0003] European patent application EP 01114694.1 filed on Jun. 19, 2001by the Applicant describes a process of linking several communicationbuses using wireless communication networks or radio networks. Thisapplication describes communication devices capable of wireless dialogor radio devices called “wireless boxes” which perform the portalfunction between a wired IEEE 1394 network and a Hiperplan 2 wirelesscommunication network. One of the features of these devices is theiroperation in pairs. In effect, a given radio device can communicatewirelessly only with one other radio device designated as its associate;for this, each radio device knows an identifier specific to itsassociate which enables it to distinguish the latter from all theothers. In European patent application EP 01114694.1, the identifierspecific to each radio device is a static address called EUI-64 storedpermanently in read-accessible memory by any other peripheral requiredby the document “IEEE 1394-1995 Standard for a High Performance SerialBus”.

[0004] The simplest way of implementing this association of two radiodevices is “by construction” during fabrication, each device receives aunique identification number (for example the EUI-64 address). At thesame time, each device receives the identification number of itsassociate (it is retained in a memory such as a flash memory forexample). The two radio devices will be capable of interchanging thesenumbers using their wireless communication protocols and thus be able tocarry out wireless communications exclusively with their associate.

[0005] This procedure however has some disadvantages:

[0006] the two associates can never be separated; they cannot be usedone without the other (the problem arises, for example, at the time of arepair or of the destruction of one of the two devices);

[0007] if one and the same user possesses two pairs of radio devices, hemust then mark each of them differently in order to differentiate themwhen the network is completely reinstalled.

[0008] One aim of the invention is to propose a communication devicecapable of wireless dialog comprising:

[0009] means of wireless communication with other communication devicescapable of wireless dialog designated as being its associates;

[0010] means for communicating with the devices connected to a wirednetwork;

[0011] and characterized in that it comprises:

[0012] means for establishing a modifiable association with othercommunication devices capable of wireless dialog.

[0013] In what follows, use will be made of the term “radio device”already explained previously to designate such devices.

[0014] Another aim of the invention is to propose a modifiable method ofassociating radio devices as described above, making it possible, in theevent of separation of the initially associated devices, to create a newassociation with any other device of the same type as the one previouslydescribed. This method of association also makes it possible to modifyan initial association of a radio device with no radio device, thisgives a first association to the device. Initially, this method can beapplied to two devices only.

[0015] Thus, the present invention concerns a method of associatingradio devices as described above, characterized in that this associationis modifiable by connecting at least two of the radio devices to beassociated.

[0016] According to a refinement, the method of associating two radiodevices is extended to n devices with n being greater than or equal tothree.

[0017] According to an embodiment of the present invention, the methodsof associating two or n devices are achieved by communication over aphysical link between the devices to be associated.

[0018] According to a variant of the preceding refinement, the n devicesto be associated must be interlinked physically, that is a wired linkmust exist between them, and must not be capable of entering intowireless communication with any of their former associates (except ifthese latter are present on the bus). According to another variant ofthe above refinement, a radio device not capable of entering intowireless communication with any of its former associates is physicallylinked to a radio device capable or not of entering into wirelesscommunication with its former associates.

[0019] Other features and advantages of the present invention will berevealed on reading the description of various embodiments, thisdescription being offered with reference to the drawings attached heretowherein:

[0020]FIG. 1 is a diagram illustrating the association of two radiodevices.

[0021]FIG. 2 is a flowchart exhibiting the procedure of associating tworadio devices.

[0022]FIG. 3 is a flowchart exhibiting the procedure of associatingseveral radio devices by connecting them all to one and the same bus.

[0023]FIG. 4 is a flowchart exhibiting the procedure of associating oneradio device with a set of already associated radio devices.

[0024]FIGS. 5a and 5 b are representations of several buses linked byradio bridges.

[0025]FIG. 6 is a general diagram of a radio device and of its variousparts.

[0026]FIG. 7 is a block diagram of a radio device.

[0027] In the rest of the description, it has been decided to interlinkthe various devices via an IEEE 1394 type serial bus and via a wirelesscommunication network of the Hiperlan 2 type. The various technologiesused to illustrate the following embodiments are not exclusive, othersmay be used. Similarly, the EUI-64 address, the unique and permanentidentifier used to distinguish the devices, is not the only onepossible. The memory serial number for example can be used in its place.

[0028] There follows a description of a method used to associate two ormore radio devices by connecting them to a single wired bus. It is clearthat, once the association has been made, all the radio devices exceptone are disconnected from the initial bus to be connected to other busesintended to form a network with the initial bus. This is illustrated inFIG. 1a which shows the association of two radio devices 12 and 13connected to one and the same bus 11; in FIG. 1b, the radio device 12 isdisconnected from the bus 11 to be connected to the bus 10 in order toform a network consisting of two buses (10 and 11) linked by a bridgeformed by the two radio devices 12 and 13.

[0029] For the exemplary embodiment, the EUI-64 address has been chosenas the identifier of any device. Each radio device may include anoriginal association initialized on fabrication of the device. It hasbeen decided, for example, that the original associate of each radiodevice is the one with the EUI-64 address immediately following its own(the radio device 0 is associated with the 1, the 2 with the 3, etc.).To determine the value of the original associate, it is sufficient tomake an exclusive OR between the EUI-64 address of the radio device andthe digit 1 encoded on 64 bits. This initial association enables theuser to be able to use the devices immediately without specialmanipulation. Otherwise, the initial association can be left blank, thatis no associate is allocated to a radio device during its fabricationand the user is told that he must make the first association of thedevice himself in order to use the radio device. However, the fact thatthe device possesses an initial association or a blank initialassociation (it is not initially associated) does not modify the processof association because when he seeks to communicate with the peripheralswith which he should be associated, he will simply not try tocommunicate. In the rest of the description, the method of associatingonly two devices will be shown initially. Two variants for associating anumber n of radio devices (n being an integer greater than two) willthen be studied.

[0030] There now follows a description with reference to FIG. 2 of anembodiment of the method of associating two radio devices. The two radiodevices to be associated are connected to one and the same 1394 bus.Each new connection to the bus provokes a reinitialization of the buscalled “bus reset” as defined in the document “IEEE 1394-1995 Standardfor a High Performance Serial Bus”. The method is described for a givenradio device. The radio device in question explores the bus to findother radio devices. It is considered, for example, that each devicepossesses a specific register to indicate to the other devices whetherit is a radio device. If it finds none (20), it retains its formerassociation (27), which is either the initial association previouslydescribed or the association that it possessed before the beginning ofthe method and abandons the association process. If it finds more thanone (21), it then also retains its former association (27) because themethod described in FIG. 2 allows association between two radio devicesonly. Where appropriate, if it finds another device which is not a radiodevice, then it retains its former association and abandons theassociation process because it can be considered that, to associate tworadio devices, it is necessary to connect them to a bus that has noother connection, but this criterion is not mandatory because thepresence of other non-radio devices on the bus does not prevent themethod from proceeding. If it finds only one other radio device, it thentries to achieve wireless communication with its former associate (22).If it succeeds in this, it then retains its former association (27) andabandons the process of association because, in this case, there is noground for creating a new association since the former association isstill valid. The meaning of the expression valid association is the factthat the associates designated by that association are capable ofwireless communication with one another when an attempt is made to usethat association. In fact, the associates are all powered up and areclose enough to be capable of wireless communication. Before continuingthe process of association, the radio devices may wait for anon-mandatory human intervention (23). It may be considered that thecreation of any new association must be validated by the networkadministrator. An example of human intervention may, for example, beconsidered to be the pressing of a button situated on the radio deviceor any other enabling means. However, this human intervention is notmandatory. If the two radio devices do not succeed in reaching theirrespective former associate, they then continue the process ofassociation. Over the wired network, they interchange their respectiveEUI-64 addresses and an indication on the fact that each of them hassucceeded or otherwise in communicating with its former associate (24and 25) hence whether or not they are ready to continue the protocol ofassociation. If the two radio devices indicate that they are ready tocontinue the protocol of association, then each one enters the number ofthe other in memory (26) (in a modifiable memory, for example anon-volatile but modifiable flash memory) so as to be able tosubsequently dialog without contact. Otherwise, they interrupt theprotocol of association.

[0031] According to the present exemplary embodiment described above,the joint use of particular devices and of the method of associationmakes it possible to form a new association of two radio devices. Theoriginal association can then be modified, replaced by a new one whichis itself modifiable. Thus initially associated radio devices can beseparated, so that each radio device is usable on its own and is nolonger dependent on its initial associate.

[0032] Furthermore it can be considered that to be able to associate tworadio devices, it is necessary to connect them together without anintermediary in order to be able to form the association, the fact ofinterconnecting two devices creating a wired network. For the rest, thisvariant uses a method similar to that described above.

[0033] According to one embodiment, the method is extended to n deviceswhere n is greater than or equal to three. It may indeed be useful to beable to associate more than two radio devices to form wireless linksbetween more than two buses. The method previously explained musttherefore be modified to adapt it to the possibility that one and thesame device may have several associates. For this second example, twovariants are envisaged. The first consists in connecting all the radiodevices to be associated to one and the same IEEE 1394 type bus and inassociating them with one another under certain conditions. The secondvariant consists in fact in adding under certain conditions a new radiodevice to a set of radio devices already associated with one another. Inthis latter variant, only the radio device to be added and one of theradio devices of the previous set must be connected to the same bus.

[0034] The first variant of the enhancement consists, as is shown inFIG. 3, in connecting all the radio devices to be associated to one andthe same bus. The method previously described for two radio devices mustbe modified to adapt it to a number of associated radio devices greaterthan or equal to three. The main condition of implementation of theassociation process is that no radio device to be associated must bealready associated with another radio device not connected to the bus.This means that, by connecting them all to one and the same bus, all thedevices belonging to several distinct groups of associated radio devicescan be associated in one and the same group. In fact, as for theassociation of two radio devices, following a reinitialization of thebus to which all the radio devices to be associated are connected, eachradio device explores the bus. The process for one of them will beconsidered. If it finds no other radio device on the wired network (30),it retains its former association (35) and abandons the process ofassociation. Optionally, if it finds another device that is not a radiodevice, then it retains its former association and abandons the processof association. If it finds other radio devices on the bus, then ittries wireless communication with its former associates except thosethat are already on the bus (31). If it succeeds in this, then itsretains its former associations and abandons the process of association.Before pursuing the association, the radio devices can wait for anon-mandatory human intervention (32). If it does not succeed inentering into contact with any of its former associates, it then beginsthe protocol of association. Over the wired network, it requests theirEUI-64 addresses from the connected radio devices and a responseindicating for each other radio device whether that radio device hassucceeded in communicating with at least one of its former associates.The radio device in question receives all the responses (33) andassociates itself with each radio device that has sent a responseindicating that it has not succeeded, by entering their EUI-64 (34)addresses into a modifiable memory.

[0035] This first variant of the extension of the present invention tomore than two devices can therefore be used to associate several radiodevices with one another by connecting them all to one and the same bus.This enables the subsequent formation of bridges between several busesby means of the portals which these radio devices are. This associationis simple and is used to associate simultaneously a large number ofradio devices. To realize this association, it is necessary however tobe able to connect all the radio devices to be associated to one and thesame bus, which is not always possible. In effect, radio devicescurrently in use must not be disconnected from their bus. On the otherhand, radio devices are required which do not possess valid associationsother than those existing with radio devices connected to the bus, thatis that they cannot communicate without contact with any of theirassociates not situated on the bus.

[0036] The second variant is thus used to add under certain conditions anew radio device to a set of radio devices already associated with oneanother. The radio device to be added and one of the radio devices ofthe previous set are to be connected to one and the same bus, which canbe the bus to which the radio device already associated with a set ofradio devices was already connected. The addition of a new radio deviceon the bus provokes the reinitialization of the bus (bus reset) andtherefore the procedure of exploration of the bus by the devices thatare connected to it. Consideration is given to the method of explorationfor any one of the radio devices. If it does not find any other radiodevice connected to the bus (40), it retains its former association (46)and abandons the process of association. If it finds more than one (41),it then also retains its former association. If it finds only one otherradio device, then it tries wireless communication with its formerassociates (42). If it succeeds, then it continues the protocol ofassociation but memorizes internally the fact that it has succeeded inwireless communication with at least one of its former associates. Tobegin the protocol of association, the radio devices wait for a humanaction (43) which is in this case mandatory. The human intervention ishere mandatory because it can indeed be imagined, as in FIG. 5a, thattwo radio devices (54 and 55) are connected to one and the same bus (51)so that this bus can be linked to two other buses (50 and 52) via tworadio bridges formed by the associations 53-54 and 55-56. If the bus 52is deleted as in FIG. 5b, the two radio devices 54 and 55 must notassociate because otherwise they would form a loop. The humanintervention is therefore mandatory in this case. If all the precedingconditions are fulfilled and the association has been enabled by a humanintervention, then the two radio devices connected to the bus begin theprotocol of association via the bus: if the two radio devices still haveat least one valid association (44), then they both retain their formerassociations. If at least one of the two radio devices has no validassociation (44), then it associates itself (45) with the other radiodevice and with all its associates and vice versa.

[0037] This second variant therefore is for associating a radio devicewith a set of radio devices that already exists and this process meansthat all the radio devices used do not have to be disconnected in orderto connect them to the same bus. It is sufficient to connect the radiodevice to be added to one of the buses comprising another radio devicein order to be able to associate it with the set of radio devices thatare already present.

[0038]FIG. 6 presents the general software organization of a radiodevice. It comprises a part 60 similar to that of all the devicescapable of being connected to a 1394 bus, a layer 61 comprising thevarious applications, particularly those managing the method ofassociation, a layer 62 of convergence between the 1394 and Hiperlan 2networks and finally a layer 63 specific to the communications viaHiperlan 2.

[0039]FIG. 7 is a block diagram of a radio device 70. The radio device70 is connected to the 1394 serial bus bearing the reference 71 over aphysical interface 72 and a link circuit 73. This latter is linked tothe internal parallel bus 74 of the radio device 70. A microprocessor 75manages the radio device which also comprises an input/output managementcircuit 76 as well as a memory 77. These last three elements are alsolinked to the parallel bus 74. The radio device 70 also comprisesanother link circuit 78 and a physical interface 79 enabling it to beconnected to the Hiperlan 2 network (81) via an antenna 80.

[0040] Typically, the microprocessor takes charge of implementing themethod of association, that is the steps of exploration of the networkand the steps of communication via the wired network 70 and Hiperlan 2radio network. The information on the radio devices present after areinitialization is memorized for example in the re-writeable memory 77.

[0041] It is fully understood that modifications may be made to themethod in respect of its implementation without them departing from thescope, as defined by the claims, of the present invention.

1. A method of associating communication devices capable of wirelesscommunication each comprising means of connection to a wired network andmeans of wireless transmission, the association being achieved for thesubsequent mutual recognition of the associated wireless communicationdevices for the implementation of a wireless communication exclusive tothe associated devices, wherein an association of a given device ismodifiable by connection to a unique wired network of this device and ofat least one other wireless communication device to be associated. 2.The method as claimed in claim 1, wherein at the time of a connection ofa device, each device connected to the network performs the followingsteps: a step of verifying the presence on the wired network of othercommunication devices capable of wireless dialog; a step of memorizingin modifiable manner the identifiers of the new associates which erasesthe identifiers of the former associates.
 3. The method as claimed inclaim 2, wherein the device in question can have only one associate at atime.
 4. The method as claimed in claim 3, wherein the associationmethod is abandoned if, at the time of the verification step, the devicein question ascertains that more than one other communication devicecapable of wireless dialog are connected to the wired network.
 5. Themethod as claimed in claim 4, wherein it comprises a step of attemptedwireless communication with its former associate which is used toabandon the method if, during this step, the device in question achieveswireless communication with its former associate not being linked to itphysically.
 6. The method as claimed in claim 2, wherein the device inquestion has a plurality of associates at a time.
 7. The method asclaimed in claim 6, wherein it comprises a step of attempted wirelesscommunication with its former associates which is used to abandon themethod if, during this step, the device in question achieves wirelesscommunication with at least one former associate not being linked to itphysically.
 8. The method as claimed in claim 2, wherein the associationmethod is abandoned if, at the time of the verification step, the devicein question ascertains that other units, different from a communicationdevice capable of wireless dialog, are connected to the wired network.9. The method as claimed in claim 6, wherein it comprises a step ofcreating a physical link between a given device and only one other ofthe devices with which it can associate, which causes a phase ofconfiguration or of reconfiguration of the wired network respectivelycreated or modified.
 10. The method as claimed in claim 9, wherein theassociation method is abandoned if, at the time of the verificationstep, the device in question ascertains that more than one othercommunication device capable of wireless dialog are connected to thewired network.
 11. The method as claimed in claim 10, wherein only oneof the devices capable of dialog without contact connected to thenetwork must be able to succeed in communicating without contact withits former associates.
 12. The method as claimed in claim 11, wherein,during the memorization phase, each device is associated not only withthe other device present on the network but also with all itsassociates.
 13. The method as claimed in claim 1, wherein it comprises astep of validation by the user of the association to be achieved by themethod.
 14. The method as claimed in claim 1, wherein the wired networkused is of the IEEE1394 type.
 15. The method as claimed in claim 1,wherein the unique and permanent identifier of a device is the EUI-64address.
 16. The method as claimed in claim 1, wherein the wirelesscommunication network is of the Hiperlan 2 type.
 17. A communicationdevice capable of wireless dialog comprising: means of wirelesscommunication with other communication devices capable of wirelessdialog designated as being its associates; means for communicating withthe devices connected to a wired network; and wherein it comprises:means for detecting, on the wired network, wireless communicationdevices; means for establishing a modifiable association with othercommunication devices capable of wireless dialog.